The Institute of the Supernatural
by AngelicDaughter
Summary: Sam and Dean are hunting a demon, but can't kill it. When Jace a Clary come along and save them, the brothers start to ask questions.
1. Chapter 1

"Drop!" The deep voice sounded behind Dean, and he did just that. Short nose, double barrel shotgun in hand, he fell to the cracking concrete floor of the empty warehouse.

He looked up just in time to see the strangest demon thing get shot in the chest. It went down, but it didn't die.

They had tried everything on the damned but nothing worked. Salt; rock salt rounds, circles, blocks- didn't do shit. Holy water; dumped, sprayed, poured, swallowed- nothing, not even a fizzly. Traps; on the ceiling, on the floor, he stepped right over them.

Not to mention that he didn't even look like a demon, not the demons looked like anything, just humans. But this one defined demon. Blood red skin, pointed teeth, gibberish speaking, horned, seven feet tall, demon.

"Well, Sammy, what the fuck." Dean said, standing. Putting another round in the chest of the demon. It screeched and started to make a noise close to the sound of metal on wood and the sound of a car getting crushed, Dean thought it was talking. It was moving its black lips and moving his head as if referring to Sam.

"I don't know, it's nothing we've ever seen before Dean."

"Yeah, I got that, but how do we kill it." He asked, as they backed away from the demon slowly.

Just then, two figures shot from the dark. A streak of blonde was on the balcony above the demon and a streak of red was right behind it. The blonde streak jumped from the balcony and landed on the demons back, embedding a glowing indigo blade into the neck of the demon.

"Clary!" It was a boy. !8 or so, and very good at what he did.

The red streak shot out, jumping to the concrete floor in front of Dean and Sam.

She threw her blade and it hit home.

Dean watched as the demon screeched and imploded.

"What the hell!" Dean shouted, turning to his brother.

"Who do a couple of teenagers kill that thing with Knives when we can't kill it was a gun? That's just unfair man." He exclaimed.

Sam shrugged, putting his gun down.

"Sam and Dean Winchester. Who the hell are you?" Sam asked, with a laugh and put his hand out to the blonde.

The blonde went to stand next to the red head. He didn't move to shake Sam's hand.

"Jace Herondale." The boy said.

"Clary Fairchild." The redhead stated, holding her chin high. Jace looked down at the short girl with awe.


	2. Chapter 2

Sam looked at Dean and shrugged. He didn't seem to think the teenagers in front of him were important.

Except for one thing; "How'd you know how to kill it?" Dean asked, nodding his head in the direction of where the demon had disappeared. He still wasn't sure if it was dead. Where did the body go? Why wasn't there any demon smoke?

"We're shadowhunters. The Nephilim." Clary began, stopping short when Jace laid a clam hand on her shoulder.

Sam's eyebrows rose. "The Nephilim? You think you're the offspring of an angel and human?" Sam gave a stark laugh, Dean just looked at him.

"Wait; you're telling me that an angel- an angel- shacked up with a human?"

"This isn't right." Jace said lightly to her.

"We can hear you." Dean pointed out, bluntly.

"Well I knew that." Clary said to Jace, ignoring the two brothers. "We have to get back to the Institute, talk to Maryse; then again they're probably just madunes looking for thrills and finding the truth." Jace said, steering Clary in the direction of the exit.

Dean paused for a second.

"Excuse me?" He said. "Did we just get dissed by a couple of teenagers?" He turned to Sam. His eyebrows rose and he shrugged. "Doesn't matter; demons dead. Lets move on."

* * *

Jace&Clary POV

"Jace," Clary's voice finally sounded in Jace's muggled head. He had been thinking of the two men they had seen during the lower demon kill. They didn't have runes, scares, or anything pointing to the fact that they were Shadowhunters; but he had seen the way they fought.

"Did you see the way they moved? How the acted together instead of just going for the kill, working together to kill it together." He looked down at Clary, she had a small, adoring smile on her lips. "What?" He asked with his own smile.

"Nothing," She said with a laugh. "Just you; you're so fascinated, what made you leave before you found out who they were?" She asked, taking his hand as they walked back to the Institute.

"I don't know. I thought they weren't important at the moment." He looked up at the passing cars.

"And now?" Clary asked in a low voice.

"Now I'm curious."

* * *

Case POV

He saw it, the whole thing. He had no choice but to freeze with the Nephilim dove in. He would have went in and killed the demon for the brothers but they had gotten there first. He couldn't have stepped out in front of them, the Nephilim would sence what he was.

He knew of both the Shadowhunters who stood before the two vessels. Clarissa Fairchild and Jonathan Lightwood.

The two who held the blood of an angel.

Once they had left, Case moved in.

"What the hell? Do you have any idea what you just did?" He walked up to Dean and looked him in the eye.

"Didn't kill a demon? 'Cuase, honestly Case, that's all I can't think of." Dean smiled.

Sam clapped Dean on the back. "Dean," He said in a warning tone. "What?" He asked.

Cas raged.

"That was the Nephilim; offspring of Angel and Human. Cursed with ridding this planet of all its diseases."

"So like us?" He gestured to Sam and him. Case just stared.

"Joking!"

"This isn't something to joke about; they were suppose to find out about you two, and they won't. You see them again and you run the other direction; no questions." And he blinked out.


End file.
